i got RT in chemistry but my overall result is paas because of my additional subject, i had given the cuet ug exam so after the exam what should i fill in CSAS registration form when they ask about my academics qualification
Since your overall result is "Pass" (even with RT in Chemistry, due to an additional subject), you should select "Passed" as your academic qualification in the CSAS UG registration form .
Fill subject details as per your marksheet , including the additional subject that helped you pass.
Subject-wise Class 12 marks are usually not required unless a program demands them.
Official guidance: CSAS UG – Careers360